1. Field of the Invention
The invention relates generally to a reinforcement bar support system, and more particularly, to a system that transfers forces perpendicular to a wall from a vertical reinforcing bar or post-tensioning rod to a surrounding frame while permitting vertical and horizontal movement of the wall with respect to the frame in the direction of the plane of the wall.
2. Description of the Related Art
Various types of anchors are known for stabilizing walls to other walls, floors, or beams. These anchors often allow for vertical movement of the wall with respect to another wall, floor or beam. Several fixed anchors for use with an overhead frame typically are embedded in masonry mortar head joints or bed joints, and therefore limit horizontal movement of the wall in all directions with respect to the frame. Such anchors can cause problems with forces in the plane of the wall resulting from seismic activity, volume changes due to temperature drying shrinkage, carbonation or other phenomenon. In particular, it has been found that when such anchors are used, these forces can result in separation of the wall from the surrounding frame.
In addition, there are anchor assemblies that are embedded into mortar joints or grout-filled cells in masonry that allow in-plane wall movement while resisting forces perpendicular to the plane of the wall. These assemblies are used where there is no vertical reinforcement in the wall that needs to be anchored at its ends.
Thus, it would be desirable to have an apparatus that can be used to transmit forces in a direction perpendicular to a wall from the wall to the frame while permitting vertical and horizontal movement of the wall with respect to the frame when used in conjunction with a reinforced or prestressed masonry wall.
The present invention is an apparatus for attaching reinforced or prestressed masonry to its supporting frame or other structural element by receiving and encapsulating a bar built into a wall. The apparatus transfers forces in a direction perpendicular to the plane of the wall from the wall to the frame or other structural element while allowing in-plane movement of the wall with respect to the frame. The apparatus generally includes a first means for attaching the apparatus to the frame and a second means connected to the first means for receiving the bar and limiting movement of the bar with respect to the frame in one axis while permitting movement of the bar in two other axes. In particular, the second means can limit movement of the bar in a direction perpendicular to the plane of the wall while permitting movement in the plane of the wall.
More specifically, the apparatus of the present invention preferably includes a brace defining at least one adjustment slot, a face projecting from the brace and a first flange extending outwardly from the face, the first flange limiting movement of the bar. The brace is attached to the frame. The brace preferably has two parallel adjustment slots. Preferably, the apparatus also includes a second flange extending outwardly from the face opposite the first flange such that the first and second flanges define a bar receiving area. The first and second flanges each can have one end connected to the face and opposite ends that are independent of one another. The first and second flanges can be formed from the face. Alternatively, a separate piece forming the flanges can be attached to the face. The first flange preferably extends parallel to the second flange. Both the first and second flange can extend substantially perpendicular to the face. In an alternative embodiment, the first flange can diverge from the second flange, e.g., to define a truncated V-shaped bar receiving area. Both the brace and the face can be planar with the face perpendicular to the brace.
In an alternative embodiment, the apparatus includes a first planar brace defining a first adjustment slot, a second planar brace defining a second adjustment slot, a face projecting from the first and second braces and a first flange extending outwardly from the face. The first flange limits movement of the bar. The first and second brace can be coplanar. In this embodiment, the apparatus also can include a second flange extending outwardly from the face opposite the first flange such that the first and second flanges define a bar receiving area. The first and second flanges each have one end connected to the face and opposite ends that are independent of one another. The first and second flanges can be formed from the face. The first flange can extend substantially parallel to the second flange. The first and second flange can extend substantially perpendicular to the face. Alternatively, the first flange can diverge from the second flange. The first and second flanges can define a truncated V-shaped bar receiving area. The face preferably is perpendicular to the first and second braces.
In another alternative embodiment, the apparatus is used in conjunction with a plurality of bars. In this embodiment, the apparatus includes a brace defining at least one adjustment slot, a face projecting from the brace and a plurality of flanges extending outwardly from the face. The flanges limit movement of the bars. The brace can alternatively define a plurality of adjustment slots which can be parallel. Each successive pair of flanges can limit movement of a respective one of the bars. The first and second flange of at least one of the successive pairs of flanges has one end connected to the face and opposite ends that are independent of one another. The first and second flanges can be formed from the face. The first flange can extend substantially parallel to the second flange. The first and second flanges can extend substantially perpendicular to the face. Alternatively, the first flange diverges from the second flange. In this case, the first and second flanges can define a truncated V-shaped bar receiving area. The brace and the face can be planar with the face perpendicular to the brace. In other embodiments, three or four flanges may be included. In alternative embodiments, the flanges extend in a plane perpendicular, rather than parallel, to the longitudinal axis of the bar.